Where and When to Empty an RV Composting Toilet

You've heard that using an RV composting toilet is the way to go when camping in an RV. It would be great not to deal with black tanks, chemical treatments, and the occasional sewage smell wafting around.

You're all too familiar with how to find dump stations, but how do you know where and when to empty an RV composting toilet when travelling? Can your bagged solids be thrown into any trash receptacle? What about when your liquid container is full?

We've got the answers to your questions (spoiler alert: it's not as complicated as you might think!), so read on to learn all the tips on emptying your composting toilet stress-free.

How an RV Composting Toilet Works

First, let's have a quick reminder about how RV composting toilets work. It's a little different than a traditional RV toilet. 

Composting toilets have two separate chambers: one for liquids (pee) and one for solids (poo). Solids go into a storage chamber containing organic matter like wood shavings, peat moss, or coconut coir, which aids in starting the composting process. This chamber is typically emptied every 1-4 weeks, depending on the type of composting toilet you have and how often it's used. The liquids go into a removable chamber that is emptied more often, sometimes daily. Separating solids from liquids is essential to prevent unpleasant odors from emanating from the composting toilet.

"Can I drain my liquid bottle into a gray tank?" you ask. You may be able to do that depending on your composting toilet model. In both our Cuddy models, you can use our drain-away kit to link directly to a gray tank.

The humanure (solids) and organic matter are mixed with an agitator or layered as needed after each use. Your bin should look like a bucket of dirt with no foul odors. A compost toilet is easy to empty, environmentally friendly, doesn't use water, and can even be portable!

Now that you know the basics of how a compost toilet works, let's talk about where and when to empty an RV composting toilet.

The Difference Between Solid Matter, Liquids, and Toilet Paper

Ok, so the first two are easy. We've already specified what "solids" and "liquids" are. These organic materials go into your composting toilet in separate bins.

As for toilet paper, personally, we don’t recommend you add it to your portable composting loo, for two reasons:

1. Adding TP to your solids bin adds unnecessary volume, meaning you have to empty more often
2. TP will get stuck around your agitator (quite the mess to unravel - eww!)

Here’s a guide we wrote about toilet paper to help you with all those questions you are probably asking right now - Can you put toilet paper in a composting toilet?

When to Empty Your RV Composting Toilet

Some benefits of composting toilets are that you don't have to empty them as often as you might think, you don't have to worry about emptying your black water tank, and you won't be using your precious water supply for a flush toilet.

This means you can be out longer and stay off-grid for extended periods with less of an environmental impact.

How long you can stay out will depend on the capacity of your composting toilet and how many people are using it. With one person using the original Cuddy full-time, you'll need to empty the solids tank every 2-4 weeks, and your liquid tank will last 1-2 days. Our Cuddy Lite will last about a week for solids and 1-2 days for liquids. This is because Cuddy Lite doesn't have an agitator.

One huge perk of the Cuddy and Cuddy Lite is the liquids tank indicator! When it's time to empty your liquid tank, a little red LED light turns on, so you never have to worry about accidentally overflowing. The tank is also solid black, so no one can see your pee sloshing when you empty it, allowing you to dump it discreetly.

Where to Dispose of Your Composting Toilet Contents

Now for the question of the hour: WHERE can you dispose of your solids and liquids?

Disposal of Liquids

Let's start with the easy one: disposal of liquid matter. Your urine container can be emptied in various places, such as into a regular toilet, pit toilet, porta-potty, or even on the ground under certain circumstances. Here are some tips for each type of disposal method:

• Regular toilet: A liquid waste container, like Cuddy's, can fit discreetly into a reusable grocery bag and be taken into a public restroom at National parks, campgrounds or rest stops. Simply dump the contents into the toilet (pro tip: flush as you dump to eliminate splashing). 
• Pit Toilet: Many trailheads have pit toilets available that you can empty your liquids bin into.
• Porta-Potty: Some public attractions and National Parks have porta-potties on site. This is our least favorite option since most porta-potties are a little gross, but in a pinch, it will work for your needs.

On the ground: If you are boondocking on public land, you can empty your liquid container on the ground, 200ft away from a water source. Always abide by Leave No Trace principles, and ensure you pick a location well away from where you (or anyone else) are camping. Urine can attract wildlife, so it's recommended that you dispose of it over hard ground or rocks so it evaporates quickly and wildlife doesn't attempt to dig in the ground to get to your pee (they love the salt!). We recommend pouring it on a mature tree to act as a fertiliser. Never empty your liquid container in city streets or parking lots. Instead, try a public bathroom at city parks.

Disposing of Solids

Now for the one that takes a little more research. Where do you dispose of your solids? Since there's human poop in there, there are some considerations to make before you empty your solids bin. 

Remember that even though your solids bin may look and smell like compost, it's not actually compost yet. The composting process for human waste takes up to six months, so please don't throw it out on the ground or in your garden just yet.

Here are some other options for where to put your solids when you empty your RV composting toilet: 

• An approved garbage receptacle: Most public garbage receptacles that allow diapers are also safe to put your bagged solids in. We suggest you always check with your local state, county, or National Parks authorities to ensure it's legal. Some counties, such as Grant County in Utah, have ordinances that forbid you to put humanure (some people reference it as human waste) in public garbage receptacles, so you'll need to plan your disposal schedule accordingly.  
• Compost Pile: If you're a weekend traveler and have a home base with a garden and compost pile, you can empty your solids bin right on top of your compost pile when you get home. This is our favorite (and most eco-friendly!) method since it allows the composting process to continue to completion. Having a compost pile at home is a great solution to starting and ending your trip with an empty RV toilet. Remember it takes 6-12 months for the compost to be pathogen free.

We don't recommend burying your solid matter on public land since it isn't completely composted. It's unlikely that you would be able to dig a deep enough hole to dispose of the amount of solid matter in your bin so that wildlife wouldn't be tempted to dig it up. Burying your solid matter also slows the composting process since there is limited airflow, and it won't be stirred.

Emptying Your RV Composting Toilet is as Easy as 1, 2, 3

So there you have it. Emptying your RV composting toilet is easier than you thought! Just follow these three tips: 

1. If you're not sure where to toss your solids, call local authorities such as the forest service, BLM office, National Park, or even the local visitor center. 
2. Remember that your solid material isn't quite compost yet. This means that you need to dispose of it the same way you would a diaper. 
3. Bring a reusable grocery bag with you so you can discreetly carry your liquids container to a regular toilet, pit toilet, or porta-potty to empty it if needed.